Update: Anonymous is not attacking Facebook today.
News broke yesterday that the hacktivist group Anonymous is vowing to destroy Facebook on November 5, 2011 (Guy Fawkes Day). Now there is speculation that it's all just a hoax. After a little digging, I've found that the collective group Anonymous doesn't support what a few of its members are reportedly up to.
I contacted Facebook last night to see what the company thinks about a possible Anonymous attack. Facebook did not get back to me, so today I decided to look for more information myself. First, let's look at how this all started.
On July 16, 2011, someone created accounts for an "Operation Facebook" on YouTube (FacebookOp) and Twitter (OP_Facebook). These account names are a little odd: why not just use one of the many other mediums that Anonymous has used in the past? Furthermore, the released video, embedded above, is not of the usual computerized voice and visual production quality that we're used to from Anonymous.
The dates are also questionable: why didn't this news spread like wildfire three weeks ago? Whenever Anonymous or LulzSec declare a new target, the world definitely notices. Furthermore, while Guy Fawkes Day is a perfectly understandable choice, it's very far away. There are 112 days between July 16, 2011 and November 5, 2011: Anonymous rarely gives more than a few days notice, if at all.
My suspicions were confirmed via a few Twitter accounts that Anonymous has previously used to talk to the media and the general public. They have given accurate information regarding the organization and its actions in the past, so I'm not as hesitant to believe what they are saying.
GroupAnon, which has some 26,000 followers, sent out these two tweets:

No one can speak for the whole of #Anonymous. There are some anons who support #OpFacebook whilst others do not. | #AnonOps
@Anonymous_SA Exactly! #OpFacebook is just an Op, it's not Anonymous...

We prefer to face the real power and not to face to the same medias that we use as tools. #OpFacebook #Anonymous
#OpFacebook is being organised by some Anons. This does not necessarily mean that all of #Anonymous agrees with it.
Dont be silly. Important things are happening in the world to deal with quirks like #OpFacebook. Lets keep our style & moral #Anonymous
TO PRESS: MEDIAS OF THE WORLD... STOP LYING! #OpFacebook is just ANOTHER FAKE! WE DONT "KILL" THE MESSENGER. THAT'S NOT OUR STYLE #Anonymous

By contrast, here is the only message from the OP_Facebook account, which has some 3,000 followers:

spread the new video like AIDS NOU!!! youtube.com/watch?v=SWQTS8…

Also, here is the original "press release" from the YouTube video posted by FacebookOp:

Attention citizens of the world,
We wish to get your attention, hoping you heed the warnings as follows:
Your medium of communication you all so dearly adore will be destroyed. If you are a willing hacktivist or a guy who just wants to protect the freedom of information then join the cause and kill facebook for the sake of your own privacy.
Facebook has been selling information to government agencies and giving clandestine access to information security firms so that they can spy on people from all around the world. Some of these so-called whitehat infosec firms are working for authoritarian governments, such as those of Egypt and Syria.
Everything you do on Facebook stays on Facebook regardless of your "privacy" settings, and deleting your account is impossible, even if you "delete" your account, all your personal info stays on Facebook and can be recovered at any time. Changing the privacy settings to make your Facebook account more "private" is also a delusion. Facebook knows more about you than your family. http://www.physorg.com/news170614271.html http://itgrunts.com/2010/10/07/facebook-steals-numbers-and-data-from-your-iph....
You cannot hide from the reality in which you, the people of the internet, live in. Facebook is the opposite of the Antisec cause. You are not safe from them nor from any government. One day you will look back on this and realise what we have done here is right, you will thank the rulers of the internet, we are not harming you but saving you.
The riots are underway. It is not a battle over the future of privacy and publicity. It is a battle for choice and informed consent. It's unfolding because people are being raped, tickled, molested, and confused into doing things where they don't understand the consequences. Facebook keeps saying that it gives users choices, but that is completely false. It gives users the illusion of and hides the details away from them "for their own good" while they then make millions off of you. When a service is "free," it really means they're making money off of you and your information.
Think for a while and prepare for a day that will go down in history. November 5 2011, #opfacebook . Engaged.
This is our world now. We exist without nationality, without religious bias. We have the right to not be surveilled, not be stalked, and not be used for profit. We have the right to not live as slaves.
We are anonymous
We are legion
We do not forgive
We do not forget
Expect us

If Facebook is indeed attacked on November 5, 2011, it does not appear that Anonymous as a whole will be supporting the hacks.
See also: